Shell Rotella T

[Eric_R_Kissell at whirlpool.com]

"Andrew Buc" <abuc at attglobal.net> wrote:
>After hearing a lot about Shell Rotella T synthetic oil (www.rotella.com),
>I thought I'd try it on my next oil change, and I got a gallon from
>Overlake Oil,Kirkland, WA. I'd been paying about $24 a gallon for Amsoil,
>and I was pleasantly surprised to find that Rotella T is $10 less.

Why were you paying $24 per gallon for Amsoil? Is that what dealers charge
for Amsoil? I have a commercial account, so I get good prices. I suppose
with dealer mark-up and shipping to Washington, Amsoil might cost around
$20 per gallon. My Amsoil prices are competitive with the $14 you quoted
for the Shell Rotella T. When I buy oil, I pay a slightly more than $14 per
gallon for the "normal" grades of Amsoil, but I could actually pay a little
less than $14 for a grade of Amsoil that I believe is still better than the
Rotella T. These are my prices before shipping.

Have you been using Amsoil Series 2000 Racing Synthetic Motor Oil? That is
a little bit more expensive. I really do not see the need for the Series
2000 unless you actually have a severe use application like racing, and
even then the normal Amsoil synthetic is likely more than adequate with
more frequent changes.

The bigger question is which grade Amsoil should we compare to Rotella T?

I have seen nothing indicating that it should be compared to anything other
than Amsoil XL-7500 Synthetic, which has a suggested change interval of
7500 miles or every 6 months, whichever comes first. Again, this grade of
Amsoil actually cost me less than $14 per gallon before shipping.

I am not trying to bash Rotella T and I am not trying to sell Amsoil. I am
sure Rotella T is a fine synthetic, but when I look at the properties it
does not look as good to me as any comparable Amsoil grade. I have not seen
detailed test reports, but when I compare Viscosity Index, Pour Point, and
Flash Point, the Rotella T is not as good as Amsoil, or Mobil 1 for that
matter. I will try to show this in a table below.

                Amsoil   Amsoil  Shell   Mobil 1  Amsoil  Amsoil
                Synth    XL-7500 Rotella Synth    Synth   Series
                Oil      Oil     T       Oil      Oil     2000
Grade           10w40    10w40   15w40   15w50    20w50   20w50

Kinematic Visc
@100C,cSt       14       14.5    15.5    17.4     18.1    18.3
Kinematic Visc
@40C,cSt        79.2     80.9    108     125      126     128.1

Visc Index      183      178     141     153      161     160

Pour Point C    -48      -42     -24     -45      -38     -36

Flash Point C   232      232     213     230      236     234

The comparison is a little funny because of the different multiple
viscosities involved, but you can get an idea. The Kinematic Viscosities
will correlate pretty much with grade, so the other characteristics are of
more interest. The pour point and flash point for the Rotella T are
particularly noteworthy.  The 15W40 Rotella T has a somewhat higher (worse)
pour point than the Mobil 1 and Amsoil grades. The 15W40 Rotella T has a
somewhat lower (worse) flash point than the Mobil 1 and Amsoil grades.  The
viscosity index is a bit lower than I expect from a synthetic motor oil as
well.

Rotella T may be better than conventional dino oil, but I am going to stick
with my competitively priced and better Amsoil when I change my oil every 6
months.

YMMV,
Eric Kissell
1991 200q 20v Avant, MRC chips, Koni Sports (yellow), "eBay Surprise"
1989 200q 10v Avant, Boge Turbogas, 1.8 Bar (qlcc)
1986 5000cstq Sedan, Bilsteins, 1.8 Bar (SJM)